Heavy equipment of the earth moving type or framing type is normally left at the end of a working day in the open at or near the place it has been used. These machines are too heavy and move too slowly to consider driving them to a garage, warehouse, or other building for safekeeping overnight. Such machines are always equipped with an ignition lock but thieves have become adept at bypassing a locked ignition and in readily being able to start the engine of such a vehicle. In more recent times there has been a marked increase in the theft of these heavy equipment vehicles and this had led to the consideration of other means for securing such vehicles from theft. It is an object of this invention to provide a means for blocking the main hydraulic fluid line to prevent its use in moving any of the auxiliary equipment of the vehicle. Thus, in case of a bulldozer the heavy blade could be left on the ground and this would prevent movement of the vehicle even though the ignition were bypassed. In other types of vehicles it would be an added delaying deterrent which might frustrate the thief and cause him to cease further attempts at stealing the vehicle because it would take too much time to make it operate properly.